NEW YORK: General Motors will pay nearly $146 million in penalties for underestimating emissions produced by its vehicles, federal regulators said Wednesday.

The American auto giant was fined after approximately 5.9 million vehicles were found to release more emissions than reported, a National Highway Traffic Safety Administration (NHTSA) spokesperson told AFP.

The vehicles in question, with model years between 2012 and 2018, showed more than 10 percent higher carbon dioxide emissions in tests, on average, than what GM reported, according to the Environmental Protection Agency (EPA).

Additionally, GM agreed to write off greenhouse gas credits that equate to approximately 50 million tons of CO2, the EPA said, with a market value of hundreds of millions of dollars.

GM shares fell 0.51 percent Wednesday on the New York Stock Exchange.